NJ_Hondaa

Hi Everyone,
I'm driving Accord 2007 SE(automatic-v4-75000 mileage).
Today I found one strange thing in my accord that engine suddenly stop turning ON. It was working fine when I parked and after 30 minutes when I tried to start it was cranking but wouldn't started. On thedashboard immobilizer indication(Key Sign) comes up with continuous flashing till key reached to off position. Also D light start flashing on dashboard. It also drain my whole battery. I have couple of jump start session but, nothing works and same result. My both genuine honda keys not working as before, even for opening door or slide up/down windows.
Is that because of ECU/PCM/ECM or bad Immobilizer circuit or Main fuel relay?
Pls Help..

m90polk1

First get your key reprogrammed to the vehicle, you have an immobilizer fault and the key is not putting out he correct signal to be recognized by the immobilizer circuit and start the vehicle. I would recommend reprogramming just one to see if it fixed the issue or not. Please post updates as to what you try so I can help.

tech8

Get the battery checked first, then the charging system. The Immobilizer wouldn't not cause the door to not be able to be opened.

m90polk1

If Key is defective will cause immobilizer fault and doors not to open. Vehicles immobilizer is synched to the key, key also has radio signal to unlock doors....Faulty and neither will work. At least that's what I figure would cause the issue. You can definitely check and make sure you have correct available voltage first and if so then look to the key

tech8

An immobilizer fault would not cause the remote to not be able to operate the door locks. The Immobilizer disable the fuel system, not the doors.

How the Immobilizer works is as follows:

Immobilizer System
How the Circuit Works
The immobilizer system is designed to prevent the
vehicle from being started without the owner’s
ignition key. If an attempt is made to start the
vehicle with any other key, the immobilizer system
will not enable the vehicle’s fuel supply system.

The ignition key transponder examines the ignition
key, and then sends a coded signal back to the
ECM/PCM through the immobilizer control
unit-receiver. If the ignition key signal is correct,
the ECM/PCM will enable the car’s fuel supply
system by grounding the PGM-FI main relay 2.
The immobilizer system indicator flashes a code to
indicate that a correct ignition key has been
inserted. If the ignition key signal is not correct,
the ECM/PCM will not ground the PGM-FI main
relay 2, which will not enable the car’s fuel supply
system. The immobilizer system indicator then
flashes a code to indicate that an incorrect ignition
key has been inserted.

NJ_Hondaa

Thanks m90polk1 & tech8 for reply..
I have replace new battery and still facing problem. Even after this I takeout fuel pipe and take a look if fuel comes out to pipe but, it wasn't. So I thought its a Fuel relay problem. So, I did connect bottle fill up with fuel to fuel injector inlets directly and bypass relay.. No success.
somehow I'm able to get rid of key symbol from dashboard(via turn key to position 2 and press lock button..do 4 times and key symbol gone) and give a try but same result. Door lock Unlock working but not starting engine.
I have kobra wifi obd2 tool, tried that but, not able to communicate with ECU.
So, finally tired and tow car to nearest Honda authorized Dealer. They were working on car since Monday, Feb 27th' 17 morning but, still didn't figure out what's the problem. As they are also not able to communicate with computer. After 3 hours of diagnostics now they are advised me to change whole ECU first and then they can start work ahead. But, still they are not sure to change ECU will make car working.
Please advise what to do?
Can anybody know where do I find ECU in 2007 accord se 2.4L auto?

NJ_Hondaa

Hi All,
Thanks for helping me out by providing your knowledge when needed.
This is an update on my 2007 Accord SE vehicle. After an week honda authorised dealer finally able to troubleshoot what's going on and they advise me to change the ECU.
Once i approved it, Its just a hour thing to get my car back on road.
Still after going through all of this, I can understand what's happening and how can you check symptoms deeply.
thanks for all of you again.
Ping me if you find same problem. Would love to help.
Cheers..!!

Trbonne

I have a 2007 accord sedan 2.4 and I'm having same issue with flashing key drained battery and quits whenever it wants 2 and this time I've not had luck starting it in 2weeks help me plz